From patchwork Mon Mar 8 10:31:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Balazs Nemeth X-Patchwork-Id: 395839 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E74A1C4332D for ; Mon, 8 Mar 2021 10:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0FA76520A for ; Mon, 8 Mar 2021 10:33:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231643AbhCHKcq (ORCPT ); Mon, 8 Mar 2021 05:32:46 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:30928 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231590AbhCHKcX (ORCPT ); Mon, 8 Mar 2021 05:32:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615199543; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tzgm3Jq54JoBtwEStS2p3zfh75LFir9ok6NSzKhJVag=; b=WjVJ0FIH+3Y7Db+1KAFPx0XyXBmXj49fLVjveTjf0Dl4sfzuRX2CHyo68E5W5U2qcJcg7q ViiYGiho7FculT2xc9zOXnvb0ThkQwi9PyuLuxLtS78+bhMAGbMNlVVrHG/rFO+ksCQ9TO aqFgv+lz8/YF6QFMofIgBg1g3RugkG0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-412-JIv8FvDnMqW9ja_fv9GHLA-1; Mon, 08 Mar 2021 05:32:21 -0500 X-MC-Unique: JIv8FvDnMqW9ja_fv9GHLA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 876CE108BD09; Mon, 8 Mar 2021 10:32:20 +0000 (UTC) Received: from bnemeth.users.ipa.redhat.com (ovpn-113-99.ams2.redhat.com [10.36.113.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8239360D79; Mon, 8 Mar 2021 10:32:18 +0000 (UTC) From: Balazs Nemeth To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, mst@redhat.com, jasowang@redhat.com, davem@davemloft.net, willemb@google.com, virtualization@lists.linux-foundation.org, bnemeth@redhat.com Subject: [PATCH v2 2/2] net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 Date: Mon, 8 Mar 2021 11:31:26 +0100 Message-Id: <85e04e1e6367f19c8f538d145b32f5bb93788d8a.1615199056.git.bnemeth@redhat.com> In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org A packet with skb_inner_network_header(skb) == skb_network_header(skb) and ETH_P_MPLS_UC will prevent mpls_gso_segment from pulling any headers from the packet. Subsequently, the call to skb_mac_gso_segment will again call mpls_gso_segment with the same packet leading to an infinite loop. Signed-off-by: Balazs Nemeth --- net/mpls/mpls_gso.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mpls/mpls_gso.c b/net/mpls/mpls_gso.c index b1690149b6fa..cc1b6457fc93 100644 --- a/net/mpls/mpls_gso.c +++ b/net/mpls/mpls_gso.c @@ -27,7 +27,7 @@ static struct sk_buff *mpls_gso_segment(struct sk_buff *skb, skb_reset_network_header(skb); mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb); - if (unlikely(!pskb_may_pull(skb, mpls_hlen))) + if (unlikely(!mpls_hlen || !pskb_may_pull(skb, mpls_hlen))) goto out; /* Setup inner SKB. */